The present invention relates in general to x-y tables and, more particularly, to supporting and drive systems for x-y tables. Such tables are widely used in a variety of equipment to achieve accurate positioning of a workpiece, a subject to be viewed, or the like, such items hereinafter being referred to as the load on the table. Examples of equipment utilizing x-y tables include milling machines, microscopes, measuring apparatus, to name but a few.
One typical prior x-y table supporting system comprises two parallel x tracks and two parallel y tracks arranged in perpendicular relation, one pair of tracks being movable with the table and the other being stationary. Such a supporting system further includes four x bearings, two of which are spaced apart along one of the x tracks and the other two of which are spaced apart along the other of the x tracks, and four y bearings, two of which are spaced apart along one of the y tracks and the other two of which are spaced apart along the other of the y tracks. The respective x and y bearings are interconnected and superimposed to provide four pairs of interconnected, superimposed bearings each of which pairs comprises one x bearing and one y bearing. The bearing pairs are movable along one of the pairs of tracks, while the other pair of tracks is movable relative to the bearing pairs and with the table. Normally, the bearings of each pair are directly superimposed, i.e., the centers of the bearings of each pair are spaced apart along a vertical line. Suitable x and y drive means are provided for driving the table in the x and y directions.